package com.example.study.utils;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;

@ControllerAdvice
@ResponseBody
public class GlobalExceptionHandler {

    private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionHandler.class);


    /**
     * 缺少参数异常
     * @param ex
     * @return
     */
    @ExceptionHandler(MissingServletRequestParameterException.class)
    public JsonResult HandleHttpMessageNotReadableException(MissingServletRequestParameterException ex){
        logger.info("缺少请求参数:{}",ex.getMessage());
        return new JsonResult(400,"缺少必要的参数");
    }


    /**
     * 空指针异常
     * @param ex NullPointerException
     * @return
     */
    @ExceptionHandler(NullPointerException.class)
    @ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR)
    public JsonResult handleTypeMismatchException(NullPointerException ex) {
        logger.error("空指针异常，{}", ex.getMessage());
        return new JsonResult(500, "空指针异常了");
    }

    /**
     * 系统异常 预期以外异常
     * @param ex
     * @return
     */
    @ExceptionHandler(Exception.class)
    @ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR)
    public JsonResult handleUnexpectedServer(Exception ex) {
        logger.error("系统异常：", ex);
        return new JsonResult(500, "系统发生异常，请联系管理员");
    }
}
